Method of making glass wool



Oct. 10, 1939. G, SLAYTER 2,175,225

METHOD OF MAKING GLASS WOOL Original Filed Oct. 11, 1934 2 Sheets-Sheet 1 1 EN TOR.

ATTORNEY Oct. 10, 1939. a. SLAYTER 2,175,225

METHOD OF MAKING GLASS WOOL Original Filed 001:. 11, 1934 2 Shee'ts-Sheet 2 //6 INVENTOR. BY 2 W ATTORNEY Patented a. 10,1939

PATENT OFFICE METHOD ornaxmc GLASS WOOL Games Slayter, Newark, Ohio, assignor, by mes ne assignments, to Owens-Coming Fiberglas Corporation, a corporation of Delaware Application October '11, 1934, Serial to. 741,921 Renewed November 4, 1937 9- Claims.

My invention relates to the, manufacture of wool from glass or like materials, which com-' At the present time there is in vogue a process.

10 of making glass wool which comprises subjecting a fine stream of molten glass to a blast of steam or other gas under considerable pressure by which the stream of glass is blown'into threads or filaments whichare collected as glass wool.- This method is satisfactory for making comparatively coarse wool adapted for certain purposes, but is not suited for making very fine wool, such as is required for some other purposes.

- I have discovered that a very fine quality of 0 such Wool material can be made by subjecting a glass rod to the action of a high temperature blast as in the now well known metal layer machine. Glass acts 'difierentl'y from'ordinary materials when fed through such a machine, and may be drawn into fine filaments of microscopic diameter and relatively great length, instead of being blown out into a spray of more or less spherical. drops as in the case of the ordinary tion of the blast, such action being arrested be- I fore the filaments have been drawn out. to the fineness that would otherwise be attained. It is found that within considerable limits, the fineness of the filaments produced is substantially proportional to the temperature of the material at the point where it is acted upon by the blast. Attempts have been made to overcome this defect by applying electrical heat to the material just before or at the point where it passes into the blowing nozzle. But this expedientis not altogether satisfactory for various practical reasons which will readily suggest themselves to those skilled in the art.

On the other hand, the metal layer method of producing glass wool from a previously formed glass rod is subject to the objection that the process cannot be made continuous without various complications goncerned with the feeqin in of successive rods as they are used up in turn in this operation to say nothing of the expense of providing the glass in the form of rods, which'is relatively large as compared with producing the wool directly from the molten batch. 5

Thepresent invention is designed to combine the advantages and avoid the disadvantages of both of the above-mentioned methods of producing glass wool, and consists, in effect, of a combination of the foregoing methods, brought about by withdrawing a continuous stream of glass from the forehearth of a melting furnace; allowing it to cool and harden or solidify to a wax-like consistency while still highly heated, and then directing the hot glass rod thus formed into and through the metal layer machine or other reducing machine in place of the cold and solid rod heretoforethought necessary in such machine method of glass woolproduction.

By this combined operation, I achieve a marked saving in fuel consumption in the melting furnace, the forehearth temperature of which is not required to be higher than that necessary to the proper melting of the batch and its delivery from the boot orifice at a proper flowing temperature of about-2100", while at the same time enabling the filament forming operation to take place at the higher temperature found necessary to the production of very fine fibers which in some instances are as small-as two'microns in diameter.

In the accompanying drawings:

Fig. 1 is a side elevation, partly in section, of an apparatus adapted for practicing my method of making glass wool.

Fig. 2 is a sectional view of the reducing machine for reducing or drawing the glass' to fine filaments.

Fig. 3 a side elevation, partly in section, of the apparatus assembled in.a slightly different manner. Y

With reference to Fig. 1, the forehearth or boot 5 of the usual type of glass furnace is provided on its lower face with an orifice 6. Adjacent the furnace is a reducing machine I mounted on suit-' able supports, the machine being adapted for receiving and reducing a partially solidified fiow of glass to the form of wool, as hereinafter more fully described.

The machine may be supplied with air under pressure from an air pressure tank 8. v The air is conducted from the tank through a tube 9 to a burner in the machine. Oxygen is supplied from a tank l0 through a tube II, and acetylene gas is likewise supplied from a tank [2 through a tube l3, to the burner in the machine I. Forward 5 of the furnace is endless-conveyor ll mounted' chine at the axis of the burner, through which the glass I1 is anism.

fed by the usual feeding mech- In operation, a stream of molten glass I1 is allowed to flow from the -forehearth li of the glass furnace through the orifice 6. continuously flowing stream assumes a partially solidified state as it becomes cooled by the comparatively cold surrounding atmosphere so thatit can be manipulated and into the passageway l6 of the machine. Ifdesired, a'cooler may be provided for additionally cooling and adjustably regulating the temperature of the flowing stream.

The cooler comprises'achamber 2| surrounding, the stream IT, -Water or other cooling medium circulates in said chamber. I

The feed mechanism in the machine I engages the advancing end of the viscous flow and feeds it forward to the burner l5. At this point the glass. mass has cooled sufllcie'ntly to retain a shape and be capable of manipulation. Nevertheless, it is still at a high temperature, preferably about 1000 F. Resultantly, when it is subjected to the heat from the burner l5, it is readily remelted. Thus, the tip of the adyancing mass melts away at a'point immediately beyond the burner. Si-

multaneously, this very fluid remelted glass on ,the outer surface of the fast melting tip is subjected tea-blast of air from the pressure tank 8, which carries away minute threads-of glass. The fluid glass is drawn out-by the pressure of the burner 'fiame into a fine filament or filaments which are carried forward at a high velocity by the gases of combustion and the forward air currents induced thereby. The fine glass filaments, as they pass beyond the zone of intense heat, are immediately cooled and solidified and also disrupted from the oncoming glass. The filaments of glass thus produced rapidly accumulate to form a mass of fine glass wool. As the force of the blast is diffused and-spent by the time thefilaments are thrown a distance from the machine, they fall on the endless conveyor H, by which they are carried to suitable receptacles.

It should be observed that the glass, while softening or melting and while drawn out to form fine fibers, is still connected to the unmelted flow or supply body, which serves as an anchor to hold the threads while they are being stretched out to form the filaments finally obtained by the force of the blast. Thisanchorage makes it possible to draw out much finer filaments than would otherwise be possible.

Referring to Fig. 3, it is seen that the machine I is positioned directly below the orifice 6 of the forehearth 5 in such a manner as to obviate manipulation of the stream of molten glass ll.

The stream I! will leave the orifice 6 and fall directly into the passageway l6 of the machine. The blast is directed downward and the filaments will be ejected downward onto a suitable conveyor below (not shown).

In the copending application of John H. Thomas, Jr., and myself, filed December 27, 1932,

Serial Number 848,953, we have illustrated and described a method of manufacturing glass wool .of operation of the machine is concerned, is

described above.

4 which, so far as general construction and method method of treating a preformed vitreous mateglass filaments by directing a sti-eam of molten glass into the machine to blowit into filaments.

Modifications may be resorted to within the spirit and scope of. my invention.

What .I claim is:

lfThe method of producing filamentous glass consisting of flowing a stream of glass continuously from a molten pool, reducing the tempera ture of the molten stream of glass toa point where it assumes a semi-solid state, and subjecting a portion of the semi-solid mass to a high temperature blast'within a confined area by which the reheated portion is progressively remelted and blown from the main body of the mass toform elongated fibers. a

2! The method whichcomprises continuously flowing a stream of glass from a pool of molten glass, and reducing the continuously flowing mass of glass to filamentous fibers, which comprises subjecting the free end of the flow to a high temperature blast while still integral with said stream and pool, and thereby causing a fiuid portion to be attenuated and'disrupted from the main body,

and then subjecting the attenuated portion to a relatively intense cold, the temperature of said blast being higher than the temperature of said 'free end to cause said glass and causing it to assume a fluent -condition, and drawing it by the force of the blast to fine threads or filaments while still anchored to the comparatively cool glass.

4. The method which comprises flowing a stream of glass from a molten pool, causing said stream to-cool to a condition of partial solidification, subjecting the advancing end of the stream to a blast of'such high temperature and force that it causes a continuous remelting of the end of the stream by said high temperature, and a drawing of the remelted glass into fine filaments by the force of the blast.

5. The method which comprises -fiowing a stream of glass from a molten pool, causing said stream to cool to a condition of partial solidification, remelting the end of the stream while still integrally united with the pool, and simultaneously applying a drawing force to said through a high temperature blast by which the advancing end of the stream is drawn out into filaments of microscopic diameter..

10 elongated filaments of microscopic diameter.

8. The process of blowing a body of molten glass to filaments of microscopic fineness, which comprises flowing a stream of the molten glass through an open space, cooling and partially solidifying the glass and changing its direction of flow as it passes through said space, progressively heating and liquefying the advancing end of the stream, and drawing the liquefied glass to a fine filamentary form.

9. The process of blowing a body of molten glass to filaments of microscopic fineness, which comprises flowing a stream of the molten glass through an open space, cooling and partially solidifying the glass and changing its direction of flow as it passes through said space, progressively heating and liquefying the advancing end of the stream by an intensely hot blast of gas, and causing the liquefied glass to be drawn to fine fibrous form by the force of the blast and while still integral with the oncoming stream.

GAMES SLAYTER. 

